Document U.S. Pat. No. 7,608,127 describes composite materials consisting of a metallic matrix of precious metals or precious metal alloys, reinforced with a filler material of tungsten carbide or molybdenum carbide. During its manufacture, this composite material is obtained by infiltration of the liquid metal, under pressure, in a preform of tungsten carbide or molybdenum carbide. The composite material described in this document may have a metal concentration ranging from 56 to 75% by weight and a hardness greater than 171 VHN, possibly exceeding 500 VHN.